const thenFs = require('then-fs')
const path = require('path')

thenFs.readFile(path.join(__dirname, './files/a.txt'), 'utf8')
  .then(data => thenFs.writeFile(path.join(__dirname, './files/c.txt'), data, 'utf8'))
  .then(() => {
    console.log('成功！')
  })
  .catch(err => {
    console.log('失败！')
    console.log(err.message)
  })


